What do Charles Dickens, Benjamin Disraeli, William Gladstone, and Tim Jones have in common?

I leave you to cogitate over the more obvious parallels in literary and political acumen shared by these well known London gentlemen – they are irrelevant to the point. More pertinent is that we have all four, variously over two centuries, enjoyed roast beef in the Grand Divan at Simpson’s-in-the-Strand; roast beef served in the traditional manner: carved at the table, with a good dollop of coarsely shredded horseradish sauce.

For me, the recent occasion for this most English of dining extravagances was my wife’s birthday. She with whom, amongst the chandeliers and paneled oak, I once again shared a fulfillment that only the stimulating permeation of allyl isothiocyanate into nasal mucosa can deliver.

In truth, I had no idea what caused the alarming pungency of the horseradish, and no amount of distracted shuffling of fork about the savoy cabbage and roast potatoes helped explain the strange sensation – quite unlike the ‘hotness in the mouth’ of a curry or the ponderous burn of ginger. So what’s it all about?

It turns out the active ingredient in horseradish – allyl isothiocyanate – is a volatile irritant. Being volatile, it can quickly get to the nasal passages where the endings of the trigeminal nerve complex come close to the surface. On the other hand, the main active compound in chili and curry, capsaicin, is a non-volatile, oil-soluble, molecule that travels most readily through the lipid membranes of the oral cavity; it makes your mouth and tongue feel hot. Interestingly, the menthol found in mint is both volatile and oil soluble, giving us that difficult to describe sensation of heating and cooling in both nose and mouth.

I also discovered during my research that allyl isothiocyanate is used to make adhesive for sailmaking, and stumbled across this patent describing the applications of horseradish as a treatment for nasal and sinus dysfunction, delivered by literally squirting the stuff up your nose. Something to try between courses maybe?